This invention relates to a polyalkylene terephthalate resin composition in which moldability is stabilized and also flame retardant properties are imparted.
Polyalkylene terephthalates represented by polyethylene terephthalate and polybutylene terephthalate have been widely used as electric and electronic equipments and components and automobile parts because of their excellent characteristics such as flex resistance, chemical resistance and electrical insulating property. Particularly, in the field of electric and electronic equipments and components, for the purpose of ensuring safety to fire, parts to which flame retardant properties are imparted have been employed in many cases.
For imparting flame retardant properties to a polyalkylene terephthalate type resin composition, an organic halogen compound and antimony trioxide are generally used in combination. However, this combination involves many problems that thermal stability is poor and fluidity of a resin is changed due to high temperatures during molding so that a resin may be flown out from a gap of a mold to be solidified, and a mold cannot be filled up with a resin in an injection cycle. In Japanese Unexamined Patent Publication No. 172050/1987, there has been proposed a technique in which flame retardant properties are imparted by using an organic halogen compound and sodium antimonate. However, even in this technique, fluid stability of a resin during molding cannot be maintained sufficiently.